Elevator cars are frequently guided along a guide rail with one or more so-called roller guide shoes in an elevator shaft. The car is usually suspended on a supporting means, in particular one or more belts or cables. The supporting means are in this case coupled to a drive machine which is usually disposed at the upper end of the elevator shaft. As a result of the elasticity of the supporting means and in the case of a large height difference between drive machine and elevator car, the elevator car executes undesirable vertical oscillations, in particular during entry and exit of passengers. However these oscillations can only be eliminated with difficulty.
One possibility for reducing these oscillations can be found in JP 01299181 A. This document describes a blocking element which attenuates these vertical oscillations. For this purpose the blocking element is arranged on a roller guide of the elevator car and consists of a piezo-electronic material. During travel this blocking element has a distance from the elevator car so that no blocking takes place. When the car stops, an electrical signal causes a volume expansion of the piezoelectric material so that the blocking element presses onto a roller of the roller guide and blocks this. The friction between roller and guide rail thus impedes the upward and downward oscillation of the elevator car.
However, such a blocking element has the disadvantage that the blocking process is associated with very loud noises. Many individual components are required and manufacture is associated with high costs. In addition, wear effects can rapidly occur, which involves a high maintenance expenditure.